How to set piston ring gaps
with a feeler gauge

Shop for Feeler Gauges

Step 1 – Place piston ring in cylinder

To check the piston ring gap, remove piston ring from piston and place it in the cylinder (bore hole).

Step 2 – Seat piston ring

Allow the piston ring to sit squarely.

Using the top of the piston, gently push the piston ring down into the cylinder.

Step 3 – Insert blade

Then, using the feeler gauge, gently ease a feeler gauge blade into the end gap and make a note of the value.

If the gap is within specification, the piston will fit properly in the cylinder and the rings will seal properly.

Step 4 – Slide gauge between piston and ring gland

Slide the feeler gauge in between the piston and the ring gland.

This will tell you how much piston ring side clearance you have.

Step 5 – Offset piston rings

Offset piston rings by approximately 120 degrees to each other before the engine’s first start.

This reduces the amount of blow by gas produced, which would otherwise cause the engine to start poorly.